Self-interference mitigation in in-band full-duplex communication systems

ABSTRACT

A system and method for mitigating self-interference in mmWave systems. A transceiver can include a mutual precoder controller that controls both an analog/RF beamforming circuit and a digital/BB beamforming circuit to prefer beams directed along paths in the local RF environment that minimize self-interference. In other cases, a transceiver can include one or more self-interference filters to internally mitigate self-interference.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a non-provisional application claiming priorityunder 35 U.S.C. § 119 to U.S. Provisional Patent Application No.62/927,673 filed Oct. 29, 2019, entitled “Frequency-SelectiveBeamforming Cancellation Design for Millimeter-Wave Full-Duplex,” and toU.S. Provisional Patent Application No. 62/967,425 filed Jan. 29, 2020,entitled “Equipping Millimeter-Wave Full-Duplex with AnalogSelf-Interference Cancellation,” and to U.S. Provisional PatentApplication No. 62/940,532 filed Nov. 26, 2019, entitled “EnablingIn-Band Coexistence of Millimeter-Wave Communication and Radar,” and toU.S. Provisional Patent Application No. 62/927,523 filed Oct. 29, 2019,entitled “MIMO Full Duplex Radios with Deep Learning,” the contents ofwhich are incorporated by reference in their entirety.

TECHNICAL FIELD

Embodiments described herein relate to wireless communication systemsand, in particular, to full-duplex wireless communications systemsconfigured to mitigate and/or cancels self-interference.

BACKGROUND

Many modern wireless communication systems, such as fifth-generationcellular (“5G”) and 60 GHz Wi-Fi (“WiGig”) are designed to leveragehistorically unused spectrum between 30 GHz to 300 GHz, often referredto as millimeter wave or “mmWave” frequencies. Although such frequenciesare relatively unused—and, thus, substantial theoretical bandwidth isavailable—free space path losses between devices communicating overthese frequencies present a substantial challenge for practical andscalable implementations of such systems.

Beamforming, and in particular hybrid digital/analog beamforming, is onetechnique used to overcome high path losses between base stations anduser equipment in mmWave systems. However, as with previous generationwireless communication systems, mmWave systems are fundamentallyhalf-duplex with respect to time and/or frequency resources. Moreparticularly, conventional and proposed mmWave systems are specificallydesigned to time and/or frequency duplex operation of transmit andreceive circuitry in order to avoid self-interference (e.g., poweroutput from transmit circuitry that is absorbed by the receive circuitryof the same transceiver device).

As such, by definition and design, conventional and proposed mmWavesystems are only able to operate at half of the theoretical maximumcapacity that an in-band full-duplex architecture could achieve.

SUMMARY

Embodiments described herein take the form of a wireless transceiver foran in-band full duplex radio frequency (“RF”) communication system. Insuch constructions, the wireless transceiver includes a transmit side, areceive side, and a controller.

The transmit side includes a digital input receiving a first data streamas input, a first precoder receiving the data stream as input, a digitalto analog converter receiving output of the first precoder as input, afirst RF chain receiving output of the digital to analog converter asinput, a second precoder receiving output of the RF chain as input, anda first antenna array receiving output of the second precoder as inputand configured to emit RF energy into a local RF environment.

The receive side of the transceiver includes a second antenna arrayreceiving RF energy from the local RF environment, a first combinerreceiving the received RF energy as input, a second RF chain receivingoutput of the first combiner as input, an analog to digital converterreceiving output of the second RF chain as input, a second combinerreceiving output of the analog to digital converter as input, and adigital output receiving output of the second combiner as input andconfigured to provide a second data stream as output.

The controller of the transceiver provides configuration parameters toboth the first precoder and the second precoder based on channel stateinformation. Specifically, the configuration parameters are configuredto minimize the RF energy emitted by the first antenna array thatreturns to the second antenna array.

Embodiments may include a self-interference cancellation filter couplingoutput of the second precoder to input of the first combiner. In otherconstructions, a second self-interference filter can also be includedcoupling output of the first precoder to input of the second combiner.

Embodiments may include a configuration in which the firstself-interference cancellation filter cancels a first portion ofself-interference and the second self-interference cancellation filtercancels a second portion of self-interference (also referred to as“residual” self-interference).

Related and additional embodiments may include a configuration in whichthe controller is configured (in some cases, leveraging a trainedpredictive model) to apply second configuration parameters to the firstself-interference cancellation filter and the second self-interferencecancellation filter. In such constructions, the second configurationparameters are configured to minimize the RF energy emitted by the firstantenna array that returns to the second antenna array and may bereceived at the first combiner.

Some embodiments may include a configuration in which the controller isconfigured to access a codebook to provide configuration parameters tothe second precoder.

Many embodiments include a configuration in which RF energy is emittedinto the local RF environment at a frequency between 30 GHz and 300 GHz,also referred to as millimeter wave, or mmWave. However, it may beappreciated that this is merely one example; one of skill in the artwill readily appreciate that other frequency bands, including lowerfrequencies such as 500-1000 MHz and/or 1 GHz to 30 GHz may be used.Broadly, the techniques and systems described herein can be suitablymodified to operate in any suitable band.

Additional embodiments described herein take the form of a system of RFdevices. The system includes a first transceiver (in some cases, a radartransceiver, an RF jamming system, or an electronic warfare system)having a first transmit side with a first transmit side antenna arrayand a first receive side with a first receive side antenna array. Thesystem also includes a second transceiver having a second transmit sidewith a baseband precoder, an RF precoder, and a second transmit sideantenna array. The second transceiver also includes a second receiveside with a second receive side antenna array. In addition, as withother constructions described herein, the second transceiver includes acontroller providing configuration parameters to both the basebandprecoder and the RF precoder based on channel state information, theconfiguration parameters configured to minimize the RF energy emitted bythe second transmit side antenna array that returns to the first receiveside antenna array and the second receive side antenna array.

Related and additional embodiments may include a configuration in whichthe first receive side antenna array is co-located with the secondreceive side antenna array.

Related and additional embodiments may include a configuration in whichthe configuration parameters are configured to minimize the RF energyemitted by the second transmit side antenna array that returns to thefirst receive side antenna array.

Related and additional embodiments may include a configuration in whichthe first transceiver and the second transceiver are configured tooperate in the same band.

Embodiments described herein take the form of a method of operating awireless transceiver for an in-band full duplex radio frequency (“RF”)communication system, the method including the operations of: receivingchannel state information; determining first configuration parametersfor a baseband precoder of the wireless transceiver based on the channelstate information, the first configuration parameters configured tominimize self-interference received at a receive antenna of the wirelesstransceiver; determining second configuration parameters for an RFprecoder of the wireless transceiver based on the channel stateinformation, the second configuration parameters configured to minimizeself-interference received at the receive antenna of the wirelesstransceiver; and applying the first and second configuration parametersto the baseband precoder and the RF precoder, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to representative embodiments illustrated inthe accompanying figures. It should be understood that the followingdescriptions are not intended to limit this disclosure to one includedembodiment. To the contrary, the disclosure provided herein is intendedto cover alternatives, modifications, and equivalents as may be includedwithin the spirit and scope of the described embodiments, and as definedby the appended claims.

FIG. 1 is a simplified system diagram of a mmWave communication system,such as described herein.

FIG. 2A depicts a simplified signal flow diagram of a transmitter of awireless communication system, as described herein.

FIG. 2B depicts a simplified signal flow diagram of a receiver of awireless communication system, as described herein.

FIG. 3A depicts a simplified signal flow diagram of a digital baseband(“BB”) precoder/digital beamforming controller of a transmitter of awireless communication system, as described herein.

FIG. 3B depicts a simplified signal flow diagram of an analog BBprecoder/analog BB beamforming controller of a transmitter of a wirelesscommunication system, as described herein.

FIG. 3C depicts a simplified signal flow diagram of an analog radiofrequency (“RF”) precoder/analog RF beamforming controller of atransmitter of a wireless communication system, as described herein.

FIG. 4A depicts a simplified signal flow diagram of a hybriddigital/analog beamforming controller of a transmitter of a wirelesscommunication system as described herein.

FIG. 4B depicts a simplified signal flow diagram of a hybriddigital/analog beamforming controller of a receiver of a wirelesscommunication system, as described herein.

FIG. 5A depicts a simplified signal flow diagram of an in-band fullduplex transceiver of a wireless communication system, as describedherein.

FIG. 5B depicts a simplified signal flow diagram of another in-band fullduplex transceiver of a wireless communication system, as describedherein.

FIG. 6 depicts a simplified system diagram of an in-band full duplextransceiver co-located with another transceiver operating in the sameband, system as described herein.

FIG. 7 depicts a simplified system diagram of an in-band full duplextransceiver, system as described herein.

FIG. 8 is a flowchart depicting example operations of a method of usinga hybrid digital/analog beamforming architecture for self-interferencecancellation, such as described herein.

FIG. 9 is a flowchart depicting example operations of a method of usinga self-interference cancellation filters for self-interferencecancellation, such as described herein.

FIG. 10 is a flowchart depicting example operations of a method ofcontrolling multiple co-located transceivers configured to transmitand/or receive in the same band, such as described herein.

The use of the same or similar reference numerals in different figuresindicates similar, related, or identical items.

Certain accompanying figures include vectors, rays, traces and/or othervisual representations of one or more example paths—which may includereflections, refractions, diffractions, and so on, through one or moremediums—that may be taken by, or may be presented to represent, one ormore photons, wavelets, or other propagating electromagnetic energyoriginating from, or generated by, one or more antennas or emittingelements shown or, or in some cases, omitted from, the accompanyingfigures. It is understood that these simplified visual representationsof electromagnetic energy regardless of spectrum (e.g., radio,microwave, VHF, UHF, mmWave, and so on), are provided merely tofacilitate an understanding of the various embodiments described hereinand, accordingly, may not necessarily be presented or illustrated toscale or with angular precision or accuracy, and, as such, are notintended to indicate any preference or requirement for an illustratedembodiment to receive, emit, reflect, refract, focus, and/or diffractlight at any particular illustrated angle, orientation, polarization, ordirection, to the exclusion of other embodiments described or referencedherein.

Additionally, it should be understood that the proportions anddimensions (either relative or absolute) of the various features andelements (and collections and groupings thereof) and the boundaries,separations, and positional relationships presented therebetween, areprovided in the accompanying figures merely to facilitate anunderstanding of the various embodiments described herein and,accordingly, may not necessarily be presented or illustrated to scale,and are not intended to indicate any preference or requirement for anillustrated embodiment to the exclusion of embodiments described withreference thereto.

DETAILED DESCRIPTION

Embodiments described herein relate to in-band full-duplexcommunications systems that operate to exchange digital informationbetween two or more transceiver devices across one or more millimeterwavelength frequencies (“mmWave”).

As used herein, the term “transceiver device” can refer to any suitableelectronic device or set of electronic devices configured to bothtransmit and receive wireless communications over mmWave frequencies(e.g., in the range of 30 GHz-300 GHz). Example transceiver devices caninclude base station devices, access point devices, radio head units,user equipment (“UE”), point-to-point devices, and the like. Example UEtransceiver devices can include personal or industrialtelecommunications devices, which may be stationary or mobile. Examplesinclude but are not limited to: cellular phones; tablet computers;laptop computers; vehicle communications devices; modems;Internet-of-Things devices; home or industrial automation devices; homeor business internet access devices; and so on. In other cases, thesystems and methods described herein can be leveraged by half-duplexdevices, such as transmitters, receivers, radio/communications jammingsystems, mmWave/GHz active denial systems/crowd control systems, warfaresystems, and so on.

For simplicity of description, many embodiments that follow reference abase station transceiver device configured to communicate with UE, suchas a cellular phone. It may be appreciated, however, that this is merelyone example configuration of two transceiver devices communicablycoupled, as described herein; any suitable device or pair of devices canbe configured to leverage the systems, methods, and architecturesdescribed herein.

As noted above, transceiver devices described herein can be configuredfor in-band full duplex communication across mmWave frequencies. As usedherein, the term “in-band” refers to receiving and transmitting over atleast partially overlapping bandwidths. In some cases, carrier/centerfrequencies of a particular channel may be the same, but this is notnecessarily required. For example, in some embodiments, overlappingbandwidth of adjacent channels can be referred to as “in-band” systems.

More specifically, embodiments described herein relate to transceiverdevices, and methods for operating the same, configured to cancel orotherwise mitigate (or minimize) effects of self-interference in eitheror both the radio frequency (“RF”) domain or the baseband domain (“BB”),thereby supporting simultaneous, non-duplexed, operation of bothtransmit and receive circuitry in the same transceiver device operatingat mmWave frequencies.

As a result of architectures described herein, two communicably coupledmmWave transceiver devices (e.g., a cellular phone and a base station)can communicate at substantially higher speeds than conventional mmWavetransceiver devices configured for half-duplex operation.

In a simpler, non-limiting phrasing, it may be appreciated thatconventional wireless communications devices operate transmittercircuitry only when receiver circuitry is not operating. This duplexingtechnique prevents power output from the transmitter from being absorbedby the receiver and potentially (1) damaging sensitive receiverelectronics and/or (2) overpower signal(s) transmitted by a separatetransceiver device. By contrast, embodiments described herein areconfigured to adaptively filter self-interference (in either or both BBand RF domains) so that transmitter circuitry and receiver circuitry canoperate simultaneously within the same bands.

As may be appreciated, and as noted above, mmWave communicationssystems—including those systems described and referencedherein—typically include multiple antenna elements (which may be usedfor either or both transmitting signals and receiving signals) that areoperated with one or more BB or RF beamforming techniques in order toovercome challenges introduced by substantial path losses associatedwith operating at mmWave frequencies.

For example, a base station can be configured to communicate with a UE.The base station can include an array of antenna elements sized,oriented, and distributed suitably to transmit and receive at mmWavefrequencies. A data stream can be received by the base station as input.The data stream (the BB signal) can be converted to an analog signal(encoded according to any suitable methodology) and modulated over acarrier frequency within the mmWave band. The resulting modulated signalis an RF signal that can be supplied as input to one or more of theantenna elements of the array of antenna elements. In particular, bycontrolling the amplitude and/or phase of a particular RF signal appliedas input to a particular antenna element (or subarray of antennaelements) of the array, a main lobe of RF energy, also referred to as a“beam, emitted from the array can be “steered” in a particulardirection, such as a direction along a path that terminates at the UE.In addition, as may be appreciated, side lobes emitted from the array(and/or nulls) can be likewise steered toward or away from other UE sothat the data stream intended to be received by the UE does not, itself,cause interference with other UE within the same radio environment. Thisforegoing example is conventionally referred to as “analog beamforming,”as the operation takes place in the analog/RF domain.

Collectively, information related to or otherwise describing thepropagation of a signal from a transmitter to a receiver is referred toas “channel state information.” In this manner, an analog beamformingoperation can leverage channel state information to direct a main lobeof a lobe pattern along a path (either direct or indirect; a path may beline-of-sight, or may include one or more reflections from one or moreRF-reflective surfaces in the local RF environment) that terminates atan intended receiver device and minimizes path losses (e.g., fading,power decay, scattering, and so on). In other cases, such as thosedescribed herein, channel state information can be leveraged to inform abeamforming operation optimized for other purposes and not only forminimizing path loss; as one example, beamforming can be optimized tominimize self-interference effects. Such example configurations andarchitectures are described in greater detail below.

Channel state information can be obtained and/or determined or estimatedin any number of suitable ways, as known by a person of skill in theart. As one example, a beamtraining operation can be performed by a pairof transceivers. As one simple example, a first transceiver can receivesignal quality feedback from a second transceiver as either or bothtransceivers iterate through different beamforming configurations (e.g.,different beam directions/orientations). In other examples, channelstate information can be communicated along a different communicationlink (e.g., channel state information relating to an RF environment forcellular communications, such as mmWave can be communicated betweentransceiver devices via Wi-Fi, Bluetooth, over the open Internet, and soon). In yet other examples, a transceiver such as a base station may bepositioned in a substantially stationary or fixed location. In suchcases, baseline channel state information may be known or knowable.These foregoing examples are not exhaustive; it may be appreciated byone of skill in the art that channel state information can be determinedand/or leveraged in a number of suitable ways.

In addition to, or in place of, analog beamforming, in otherembodiments, a base station can be configured to digitally modify a datastream prior to conversion to an analog signal which, in turn, may beup-converted into an RF signal applied as input to one or more antennaelements or subarrays thereof. This foregoing example is conventionallyreferred to as “digital beamforming,” as the operation takes place inthe digital/BB domain. As with analog beamforming, digital beamformingcan be informed by channel state information.

As may be appreciated, both analog and digital beamforming in mmWavecommunication systems have advantages and disadvantages. As such, manysystems are implemented to support practical implementations of hybriddigital/analog beamforming techniques. Accordingly, and for thesimplicity of description, the embodiments that follow referencetransceivers configured to implement hybrid digital/analog beamformingto facilitate mmWave communications between transceivers, although it isappreciated that the systems and methods herein can be modified and/orotherwise configured to be used for other beamforming architectures aswell.

In view of the foregoing, many embodiments described herein referencesystems and methods to leverage hybrid digital/analog beamforming forself-interference cancellation in mmWave transceiver devices, therebyenabling a mmWave transceiver device to simultaneously transmit andreceive using the same mmWave frequency bands/channels.

In particular, some embodiments described herein include one or moreanalog/RF domain self-interference cancellation (“SIC”) filters thatcouple RF transmit signals to RF receive signals within a transceiverdevice, thereby mitigating self-interference effects. Such SIC filterscan be configured to invert, phase shift, and/or otherwise modify the RFtransmit signal (received as input to the filter) in order toeffectively generate an inverse RF signal that, when injected into thereceive chain, cancels self-interference effects. Many embodimentsdescribed herein reference systems and methods for configuringparameters, coefficients, and/or other operational characteristics ofsuch filters.

In other embodiments, one or more digital domain SIC filters can beused. Such filters can be configured to tap, as input, a BB signal fromtransmit circuitry and to use that signal to effectively generate aninverse BB signal (whether digital or analog) that, when combined withthe receive chain, cancels or compensates for one or moreself-interference effects.

In many examples, a hybrid digital/analog beamforming architecture caninclude both a digital SIC filter and an analog SIC filter. In suchexamples, the two filters can be communicably coupled and/or otherwiseconfigured to cooperate such that any interference not cancelled by theanalog SIC filter in the analog domain can be canceled by the digitalSIC filter in the digital domain.

Further embodiments described herein reference systems and methods foroperating a hybrid digital/analog beamforming architecture to steernulls toward antenna arrays used for receiving signals from othertransceiver devices. In these constructions, signals transmitted by atransmit side antenna array can emit a beam formed with a main lobedirected to a path terminating at a target receiver device, and sidelobes directed away from (and nulls directed toward) antennas used forreceiving and/or directed away from other transceiver devicestransmitting data to the transceiver. In this manner, a substantialportion of energy emitted from the transmitter side of the transceivercan be steered in a direction that presents a null over a receive sideantenna array of the same transceiver. In this manner, more generallyand broadly, beamforming may be used to cancel and/or mitigate effectsof self-interference.

A person of skill in the art may further appreciate additional benefitsrealizable from the foregoing described construction. More particularly,such constructions can be configured as frequency-flat orfrequency-selective.

For example, as may be appreciated, frequency-flat beamforming, such astypically achieved by analog beamforming implementations, may not beoptimal in all environments as such constructions . More specifically,it may be readily appreciated that different frequencies may propagatethrough the same environment in different ways. As such, frequency-flatbeamforming may not be optimal for all environments (or bandwidths orcarrier frequencies), especially at short wavelengths, such as mmWavefrequencies.

Accordingly, some embodiments described herein reference systems andmethods for operating a hybrid digital/analog beamforming architectureas a frequency-selective zero-forcing transmitter (also referred to asnull steering transmitter) configured to minimize self-interference on aper-frequency (e.g., per carrier) basis. In one construction, anorthogonal matching pursuit algorithm (or other optimization algorithmsuch as a gradient descent algorithm) can be used to selectconfiguration parameters (e.g., filter coefficients) that defineoperations and behaviors of both digital beamforming electronics andanalog beamforming electronics of the transceiver. In such examples, theorthogonal matching pursuit algorithm can be provided an analogbeamforming codebook as input and may be configured to select digitalbeamforming parameters and a vector from the codebook that cooperativelyoptimize performance (and minimize self-interference) of thetransceiver.

In yet further embodiments, self-cancellation filtering can be informedby and/or controlled by output from one or more trained predictivemodels or statistical inference machines or systems, such as a neuralnetwork. More generally and broadly, a trained predictive model can beleveraged to automatically cancel or otherwise mitigate multipatheffects (e.g., echoes) resulting from full-duplex operation of atransceiver.

The foregoing example embodiments are mere examples of the variousconstructions or implementations of a system as described herein. In amore simple and non-limiting phrasing, the embodiments described hereinare directed to various methods of mitigating effects ofself-interference particular to mmWave system architectures. Forexample, beamforming can be used for self-interference mitigation,hardware (and/or software) self-interference cancellation filters can beused for self-interference mitigation, neural networks or other trainedpredictive models can be used for self-interference mitigation, and soon. Each of these techniques and structures can contribute to reductionsin self-interference which, in turn, improves the performance offull-duplex in-band communications.

It may be appreciated that the systems and methods described herein canbe leveraged for additional purposes beyond just self-interferencecancellation. For example, as may be appreciated, some transceivers asdescribed herein may be operated in environments with other devicesoperating in mmWave bands, such as radar systems. Further embodimentsdescribed herein reference constructions and architectures facilitatingthe co-operation of both mmWave radar systems and mmWave transceiversystems.

These foregoing and other embodiments are discussed below with referenceto FIGS. 1-10. However, those skilled in the art will readily appreciatethat the detailed description given herein with respect to these figuresis for explanation only and should not be construed as limiting.

Generally and broadly, FIG. 1 depicts a simplified system diagram of acommunications system as described herein. As noted above, acommunications system as described herein is typically a wirelesscommunications system including two or more transceiver devicesconfigured to exchange information modulated over one or more carrierfrequencies in the mmWave band of frequencies, which includesfrequencies ranging from 30 GHz to 300 GHz. In many implementations, asystem as described herein can be configured to communicate acrossfrequencies from 30 GHz to 100 GHz, but this is not required and ismerely one example.

Further, a person of skill in the art may readily appreciated that anynumber of suitable time division, frequency division, spatial division,or other spectrum sharing techniques can be utilized herein. Similarly,any suitable number of channels may be used, at any suitable channelwidth. In a more general phrasing, it may be appreciated that a wirelesscommunications system as described herein need not specifically conformto any particular communications protocol; any suitable communicationsprotocol or definition set may be used. A wireless communications systemcan include any suitable number of channels, spaced at any appropriatechannel spacing, having any appropriate channel width, and so on.

Similarly, as noted above, transceiver devices that form portions of awireless communication system as described herein can be implemented ina number of suitable ways. Example devices include base stations and UE,such as cellular phones. These are merely examples, and any suitableelectronic devices can form a portion of a wireless communicationssystem as described herein. For simplicity of description, theembodiments that follow reference an example construction in which awireless communications system is implemented as a cellular networkincluding a base station (a first transceiver) and a UE, cell phone (asecond transceiver).

FIG. 1 depicts a simplified representation of such a system. Inparticular, FIG. 1 shows a wireless communication system 100 thatincludes a base station 102 that is configured to communicably couple toone or more UE, such as the portable electronic device 104 and/or theportable electronic device 106.

The portable electronic devices 104, 106 can be configured in anysuitable manner and although depicted generally as cellular phones, itmay be appreciated that this is merely one possible implementation.Further example electronic devices that can participate in the wirelesscommunication system 100 and/or communicate directly or indirectly withthe base station 102 (or, more generally, a transceiver) include anycomputing resource configured to send, consume, generate, and/or receivedigital data. Example computing resources contemplated herein include,but are not limited to: single or multi-core processors; single ormulti-thread processors; purpose-configured co-processors (e.g.,graphics processing units, motion processing units, sensor processingunits, and the like); volatile or non-volatile memory;application-specific integrated circuits; field-programmable gatearrays; input/output devices and systems and components thereof (e.g.,keyboards, mice, trackpads, generic human interface devices, videocameras, microphones, speakers, and the like); networking appliances andsystems and components thereof (e.g., routers, switches, firewalls,packet shapers, content filters, network interface controllers or cards,access points, modems, and the like); embedded devices and systems andcomponents thereof (e.g., system(s)-on-chip, Internet-of-Things devices,and the like); industrial control or automation devices and systems andcomponents thereof (e.g., programmable logic controllers, programmablerelays, supervisory control and data acquisition controllers, discretecontrollers, and the like); vehicle or aeronautical control devicessystems and components thereof (e.g., navigation devices, safety devicesor controllers, security devices, and the like); corporate or businessinfrastructure devices or appliances (e.g., private branch exchangedevices, voice-over internet protocol hosts and controllers, end-userterminals, and the like); personal electronic devices and systems andcomponents thereof (e.g., cellular phones, tablet computers, desktopcomputers, laptop computers, wearable devices); personal electronicdevices and accessories thereof (e.g., peripheral input devices,wearable devices, implantable devices, medical devices and so on); andso on. It may be appreciated that the foregoing examples are notexhaustive.

For simplicity of description and illustration the portable electronicdevice 104 and the portable electronic device 106 are depicted ascellular phones; this is merely one example.

In particular, the base station 102 includes an antenna array 108 thatcan include multiple individual antenna elements. Some of the antennaelements may be dedicated to transmitting wireless information whileother antenna elements may dedicated to receiving wireless information.In other cases, different antennas or subgroups of antennas can beselected at different times to either transmit or receive wireless RFsignals. As noted below, in many constructions, certain antennas of theantenna array 108 can be operated as transmit antennas at the same timethat certain other antennas of the antenna array 108 are operated asreceive antennas. In other words, the base station 102 can be configuredto operate the antenna array 108 as a full-duplex antenna array that isconfigured to simultaneously send and receive within the same band. Suchconstructions are described in greater detail below.

The antenna array 108 can be configured in a number of ways. In manyembodiments, each antenna of the antenna array 108 is oriented to emitand/or receive RF signals of a particular polarity. In suchconstructions, each antenna can be paired with a co-located antennaoriented orthogonally. In this manner, the antenna array 108 can beformed form pairs of orthogonally oriented antennas to ensure that theportable electronic devices 104, 106 can receive signals emitted fromthe antenna array 108 regardless of the physical orientation of thosedevices.

In some embodiments, the pairs of antennas of the antenna array 108 ofcan be arranged in a planar grid. This is merely one example; anysuitable arrangement of antennas can be used upon any suitable shape(e.g., concave shapes, parabolic shapes, and so on).

As noted with respect to many embodiments described herein the basestation 102 can be configured to operate the antenna array 108 accordingto one or more beamforming techniques. Specifically, the base station102 can be configured to implement either or both BB beamforming or RFbeamforming. In many examples, hybrid BB/RF beamforming may be used.Generally and broadly, as may be appreciated by a person of skill in theart, beamforming may be leveraged to direct a substantial portion of RFenergy emitted from the antenna array 108 in a direction that follows apath that terminates at a target UE, such as the portable electronicdevice 104 or the portable electronic device 106. As may be appreciated,and as shown in FIG. 1, the path may not be a line-of-sight path; inmany practical implementations, the base station 102 may be configuredto direct RF energy into local radio environment 110, targeted toward anenvironmental object 112 that, in turn reflects the beam toward UE, suchas the portable electronic device 104.

More specifically, as understood by a person of skill in the art,beamforming operations modulate the phase, amplitude, and/or othersignal characteristics of an RF signal applied to a particular antennaelement of the antenna array 108. Similarly, RF signals applied toadjacent antenna elements are likewise configured such that aconstructive interference pattern is generated along a particular,selected, path.

For example, in one embodiment, two antenna elements are positionedadjacent to one another. If each element is supplied with the same RFsignal (e.g., same amplitude, phase, and so on), half of the energy ofthat RF signal will be emitted from the first antenna and half of theenergy of the RF signal will be emitted from the second antenna. Theenergy emitted from both antennas is in phase and thus willconstructively interfere where emitted RF energy overlaps. Thisconstructive interference pattern is typically referred to as the “mainlobe” of the antenna pair. In this same construction, if a phasedifference is introduced between the first and second antenna elements,the interference pattern changes shape and, correspondingly, the mainlobe propagates in a different direction. In this manner, phase controlcan be used to direct the main lobe emitted from the antenna pair (ofthis example) in any suitable angle.

This concept is extended to larger arrays of antennas, such as theantenna array 108. In such implementations, dozens or hundreds ofantennas can be fed with independent RF signals, each of which may haveseparate phase and/or amplitude. In some cases, the antenna array 108can be subdivided into subarrays; each subarray can receive, as input, asingle input RF signal.

However, as may be readily appreciated and as described above, phaseand/or amplitude control for beamforming/beamsteering purposes is notsuitable for all implementations. In particular, as known to persons ofskill in the art, analog beamsteering/beamforming is generally onlysuitable to direct one beam at a time from an antenna array, such as theantenna array 108. In other words, for the base station 102 tocommunicably couple to each of the portable electronic device 104 andthe portable electronic device 106, time and/or frequency multiplexingtechniques must be employed. For this reason, analog beamsteering isoften associated with, and referred to as a single user antenna controltechnique. More commonly, this is referred to as a single-usermulti-input multiple-output system, or “SU-MIMO.”

Accordingly, as noted above, the base station 102 may also be configuredto implement one or more digital beamforming/beamsteering techniquesthat modify and combine an arbitrary number of signals in the digitaldomain to generate unique signals that can be applied to individualantenna elements of the antenna array 108, thereby steering a portion ofenergy emitted from the antenna array 108 to the portable electronicdevice 104, and a portion of the energy emitted from the antenna array108. For this reason, digital beamsteering is often associated with, andreferred to as a multiple user antenna control technique. More commonly,this is referred to as a multi-user multi-input multiple-output system,or “MU-MIMO.”

Although a communication system such as the wireless communicationsystem 100 can be implemented as either a SU-MIMO or MU-MIMO system, forsimplicity of description and illustration, the embodiments that followreference an implementation supporting multiple users. Namely, theembodiments that follow reference transceiver devices configured toperform both analog beamforming and digital beamforming. In typicallyimplementations, this technique is referred to as hybrid digital/analogbeamforming.

As noted above, in many embodiments, the base station 102 and theportable electronic device 104, 106 are configured for in-band fullduplex operation. In other words, the base station 102 can be configuredto transmit signals, steered toward the portable electronic device 104,over the same frequencies and channels used by the portable electronicdevice 104 to transmit signals to the base station 102 (and/or theportable electronic device 106). To enable such communication, a numberof self-interference cancellation techniques are described herein, someor all of which may be implemented in either or both the base station102 and the portable electronic device 104.

For example, in some embodiments, null steering can be used in eitherthe base station 102 or the portable electronic device 104 to direct anull region of an emission pattern of a set of transmit antennas towarda set of receive antennas of the same transceiver device. In othercases, the base station 102 and/or the portable electronic devices 104,106 can include one or more self-interference cancellation filters thatcouple transmit chains to receive chains within the same transceiverdevice so that signals transmitted by that device are cancelled fromsignals received by that device. In yet further examples described ingreater detail below, the base station 102 and/or the portableelectronic devices 104, 106 can include one or more self-interferencecancellation filters that couple baseband transmit data to basebandreceived data. In yet further examples, one or more trained learningalgorithms (e.g., a neural network, support vector machine, and so on)can be leveraged to augment behavior of one or more self-interferencefilters and/or one or more beamforming controllers.

These techniques and structures described herein can be operatedcooperatively and/or independently to mitigate self-interference effectsthat otherwise render full-duplex in-band communication impossible.

These foregoing embodiments depicted in FIG. 1 and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

Generally and broadly, FIGS. 2A-2B depict transmit and receive signalprocessing chains, collectively referred to as, simply “transmitterelectronics” and “receiver electronics” that may be used in atransceiver as described herein.

In particular, FIG. 2A depicts a simplified signal flow diagram of atransmitter portion of a transceiver 200 of a wireless communicationsystem, as described herein. The transmitter portion of the transceiver200 is identified in the figure as the transmitter 202.

The transmitter 202 is configured to receive a data stream 204 thatincludes data to be transmitted to a remote or “target” device. In thismanner, the transmitter 202 can be referred to as the “source device”and the remote transceiver intended to receive signals emitted by thetransmitter can be referred to as the “endpoint device” or the “targetdevice.”

The transmitter 202 includes a baseband digital precoder 206 that isconfigured to modulate, modify, or otherwise adjust the data stream 204for purposes of BB domain beamforming. The baseband digital precoder 206provides digital output that can be converted to an analog signal (e.g.,by a digital to analog converter) and thereafter modulated/up-convertedinto the RF domain and provided as input to an analog precoder 208 that,like the baseband digital precoder 206 is configured to modulate,modify, or otherwise adjust output of the baseband digital precoder 206for purposes of RF domain beamforming.

Either or both the baseband digital precoder 206 and the analog precoder208 can be configured to receive, as input, configuration parametersthat define operations thereof. In many cases, such configurationparameters may be provided as a vector of coefficients. The coefficientscan be used, in one example, to define how much phase delay is appliedto a particular signal in the RF domain or the BB domain. Other examplesare possible, but generally and broadly it may be appreciated that thebaseband digital precoder 206 and the analog precoder 208 can each beconfigured to receive a unique set of values that, in turn, defineoperations of those precoders. In some cases, these values can bealgorithmically determined, whereas in other cases these values can beselected from a set of predetermined/pre-calculated values stored in adatabase typically referred to as a codebook.

Output of the analog precoder 208 is provided to one or more poweramplifiers (and/or other components) prior to being applied as input toindividual antenna elements of an antenna array 210. Each of theseelements are depicted as communicably, conductively, or otherwisecoupled via bus, which is provided to illustrate that any suitablenumber of connections, RF chains, and so on can be used in differentimplementations. As noted above, a precoder as described here—alsoreferred to as a beamforming controller—can be operated to steer one ormore lobes (and/or one or more nulls) output from the antenna array 210into the local RF environment 212.

The transceiver 200 can also include a receiver side that functionsand/or operates as an endpoint device configured to receive wirelesssignals from a transmitter, such as the transmitter 202. FIG. 2B depictssuch a construction. In particular, FIG. 2B depicts a simplified signalflow diagram of a receiver 214 of transceiver of a wirelesscommunication system, as described herein.

The receiver 214 can also be configured for beamforming filtering, inthe reverse order of operations as the transmitter 202. In particular,the receiver 214 can include an antenna array 216 configured to receiveone or more signals from the local RF environment 212 that in turn canbe provided as input to an RF domain combiner, identified in the figureas the analog combiner 218.

The analog combiner 218 can be configured to operate in much the sameway as the analog precoder 208. In particular, signals received atdifferent antenna elements of the antenna array 216 can be delayed(e.g., phase shifted) by a particular amount and then recombined. Insome implementations amplitude may also be changed. In this manner, theanalog combiner 218 can combine/overlay signals received at differentantennas, thereby increasing signal to noise ratio.

For example, if the antenna array 216 includes two antennas, and asignal transmitted toward the antenna array arrives at an angle suchthat the first antenna receives the signal 1 ns before the secondantenna receives the signal, the RF signals received at the first andsecond antennas have a 1 ns phase delay relative to each other. In thisexample, the first-received signal can be delayed by 1 ns before beingcombined with the second signal. As a result of this technique, thecombined first and second signal will constructively interfere,effectively amplifying the originally-transmitted signal. A person ofskill in the art understands this described technique of operating ananalog combiner can be referred to as receive-side beamforming, areceiver beamforming filter, and so on.

The combined signal(s) output from the analog combiner 218 can beprovided as input to a digital combiner 220. The digital combiner 220can include one or more analog to digital converters and can beconfigured to adjust the received signal in the digital/BB domain inorder to provide, as output received data 222.

As with precoders, the combiners of the receiver side of the transceiver200 can be controlled by/informed by one or more vectors of values whichmay be determined and/or obtained/selected from a codebook.

These foregoing embodiments depicted in FIGS. 2A-2B and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

For example, it may be appreciated that the example embodiment depictedin FIGS. 2A-2B can be implemented in a number of ways. For example, asnoted above, a transceiver can include both a transmitter side and areceiver side. The transmitter side and the receiver side can beconfigured to operate simultaneously or in a time, polarization, and/orfrequency multiplexed manner.

Further, it may be appreciated that a transceiver that includes atransmitter side (such as the transmitter 202) and a receiver side (suchas the receiver 214) can leverage the same antenna array or may leveragea different, dedicated, antenna array. In some embodiments a receiveside antenna array can be positioned in a different physical locationthan a transmit side antenna array. In other cases, a receive sideantenna array can be positioned adjacent to a transmit side antennaarray. In still further examples, multiple arrays can be used formultiple purposes in a multiplexed manner. For example, in oneimplementation, a transceiver includes two antenna arrays. In thisexample, the transceiver can be configured to switch between antennaarrays at a given rate. For example, for a first period of time, thefirst antenna array may be dedicated to transmitting RF energy whereasin a second period of time, the first antenna array may be dedicated toreceiving RF energy.

In yet further constructions, subarrays of an antenna array (or morethan one antenna array) can be defined and coupled to transmit circuitryor receive circuitry.

In some cases, a transmit side antenna array can include more antennasthan a receive side antenna array. In other cases, a receive sideantenna array may include more antennas than a transmit side antennaarray.

In view of the foregoing examples, which are not exhaustive of antennaor transceiver configurations as described herein, a person of skill inthe art may readily appreciate that any suitable shared or dedicatedantenna array architecture may be used with a transmitter side and/orreceive side of a transceiver as described here.

Further, although FIGS. 2A-2B depict embodiments in which a transmitterside and a receiver side implement hybrid digital/analog beamformingarchitecture, this is not required of all embodiments. In particular,some embodiments described herein can be operated with an analogbeamforming architecture (either baseband or RF) or a digitalbeamforming architecture. Examples of these architectures are presentedin FIGS. 3A-3C.

For example, FIG. 3A depicts a simplified signal flow diagram of atransmitter that includes a digital precoder only. In this construction,the transceiver 300 includes a transmitter 302 that receives a datastream 304 to transmit to an endpoint device, which may also be atransceiver such as described herein or may be a half-duplex deviceconfigured for one-way communication with the transceiver 300 (e.g.,configured to operate only to receive signals transmitted by thetransmitter 302).

In the illustrated construction, the data stream 304 is received at aprecoder 306 that, like precoders described above, can be configured toreceive as input one or more vectors of coefficients that define one ormore operations of the precoder 306. The precoder 306 operates in thebaseband, and as such, is typically a digital baseband precoder. Morespecifically, the precoder 306 is configured to modify the data stream304 to provide a digital output that, when up-converted and provided asinput to an antenna array, causes the antenna array to emit RF energyalong a particular path. In other words, the operation of the precoder306 defines, at least in part, a lobe pattern emitted by an antennaarray of the transmitter 302. The lobe pattern can include a main lobeoriented along a path that terminates at the target receiver device(e.g., the path may be line of sight or may include one or morereflections from one or more objects in the RF environment), and one ormore side lobes or null points oriented along other directions. In thismanner, operation and configuration of the precoder 306 defines thebeamforming and/or beamsteering operations/functions of the transmitter302. More particularly, the vector of coefficients received as input tothe precoder 306 defines operation of the transmitter 302.

As with other embodiments described herein, the vector provided as inputto the precoder 306 can be provided/generated/accessed or otherwiseobtained or selected by a precoder controller 308. The precodercontroller 308 can be, or can include, any suitable computing device ormemory structure configured to determine (or otherwise provide asoutput) a vector of digital values (which may be integer values, floatvalues, or any other suitable scalar values). In this construction, whenthe precoder 306 receives a vector of values, its configuration changesand, correspondingly the lobe pattern emitted from the antenna arraychanges.

In this architecture, more generally and broadly, the precoder 306 isconfigured to receive the data stream as input (e.g., can be configuredto receive digital data as input) and to provide digital values asoutput. These digital values are passed along a transmit chain,described below, to cause an antenna array to emit a differently-shapedor differently structured lobe pattern.

In particular, the precoder 306 can provide, as output via a bus 310,one or more streams of digital values as input to a digital to analogconverter 312. The digital to analog converter 312 converts the digitaloutput provided by the precoder 306 into an analog electrical signal(e.g., time-varying voltage, current, or power signal). In turn, theanalog voltage signal can be provided to baseband to radio frequencyconverter 314 which, in turn provides output suitable for amplificationby a power amplifier 316. Output from the power amplifier 316 isprovided as input to an antenna array 318, such as described withrespect to other embodiments presented herein. The antenna array 318thereafter emits RF energy in a lobe pattern defined in substantialparty by the precoder 306 into the local RF environment 320.

It may be appreciated that the embodiment shown in FIG. 3A issimplified. In particular, it may be appreciated that the depicted bus,the bus 310, is illustrated to convey that multiple independent chainsand/or communication channels can be defined from the precoder 306 tothe antenna array 318, as appropriate for particular implementations.For example, in many embodiments, a separate and discrete poweramplifier may be used for each RF chain.

Further it may be appreciated that the precoder controller 308 canperform and/or may implement one or more operations in order todetermine, modify, or select the vector applied as input to the precoder306 to change and operation of the precoder 306 and, in turn, to changethe lobe pattern emitted from the antenna array 318. For example, inmany embodiments, a beamtraining operation (e.g., to determine and/orestimate channel state information) may be performed to determine a pathor a set of paths to an intended receiver device. In some cases,beamtraining may consist of iteratively selecting different vectors froma codebook, and eventually selecting a vector that provides thestrongest signal at the receiver device. In other cases, certain channelinformation (e.g., information about the local RF environment 320) maybe known. In such cases, beamtraining may not be required; a vector canbe determined based on known or otherwise determined or estimatedchannel state information.

In still further implementations, the precoder 306 can be configured togenerate a lobe pattern from the antenna array 318 that serves multipleendpoint/receiver devices.

It may be appreciated that the foregoing described example embodimentsand use cases are simplified and that in many constructions additionalcomponents, elements, signal processing elements, analog and digitalelements may be included.

Further still, it may be appreciated that in some embodiments analogbeamforming/analog precoding may be used. FIG. 3B depicts a simplifiedsignal flow diagram of an analog baseband precoder/analog beamformingcontroller. In this construction, which may be configured in a similarmanner as shown in FIG. 3A, the precoder 306 receives input from thedigital to analog converter 312 which receives the data stream 304 asinput. In this construction, the precoder 306 may be configured toreceive configuration parameters/a vector from a codebook 322, althoughthis is not required of all embodiments. This construction differs fromFIG. 3A in that the precoder 306 operates on analog baseband data. Insuch examples, the precoder 306 in FIG. 3B may include one or moreattenuators, one or more phase shifters, and so on. Each independentphase shifter or attenuator can be configured to attenuate or phaseshift (respectively) one signal line relative to another signal linebased on one respective entry in the vector/code supplied by thecodebook 322. In other cases, a codebook 322 may be substituted for afully-digital controller, such as the precoder controller 308 shown inFIG. 3A.

In another construction, analog RF beamforming may be used. FIG. 3Cdepicts a simplified signal flow diagram of an analog RF.

FIG. 3C depicts a simplified signal flow diagram of an analog RFprecoder/analog beamforming controller. In this construction, which maybe configured in a similar manner as shown in FIGS. 3A-3B, the precoder306 receives input from the baseband to radio frequency converter 314which receives as input analog output of the digital to analog converter312. In this construction, as with the foregoing constructions, theprecoder 306 may be configured to receive configuration parameters/avector from a codebook 322 (and/or a precoder controller such as theprecoder controller 308), although this is not required of allembodiments. This construction differs from FIGS. 3A-3B in that theprecoder 306 operates on analog RF data. In such examples, the precoder306 in FIG. 3C may include one or more attenuators, one or more phaseshifters, and so on. As with the analog BB precoder described inreference to FIG. 3B, each independent phase shifter or attenuator canbe configured to attenuate or phase shift (respectively) one signal linerelative to another signal line based on one respective entry in thevector/code supplied by the codebook 322. In other cases, a codebook 322may be substituted for a fully-digital controller, such as the precodercontroller 308 shown in FIG. 3A.

These foregoing embodiments depicted in FIGS. 3A-3C and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

For example, in hybrid architectures, a single precoder controller canbe configured to mutually control operations of both a baseband precoderand an RF precoder. This construction can be leveraged forself-inference cancellation, as described in greater detail below.

FIG. 4A depicts a simplified signal flow diagram of a hybriddigital/analog beamforming controller of a transmitter of a wirelesscommunication system as described herein.

In particular, the transceiver 400 can include a hybrid precoder chain402 a that, like other embodiments described herein, receives a datastream 404 as input. The data stream 404 can be received by a basebandprecoder 406 which, as described above, can modify one or morecharacteristics or parameters of the data stream 404 in order to definea particular lobe pattern suitable to establish a communication linkwith a remote device, remote transceiver, or other endpoint device.

As noted above, the hybrid precoder chain 402 a implements a hybridarchitecture and as such also includes an RF precoder 408. As with otherembodiments described herein, the RF precoder 408 can be configured tomodify—in the RF domain—one or more characteristics or parameters of theup-converted baseband signal output from the baseband precoder 406.

Both the baseband precoder 406 and the RF precoder 408 can becommunicably coupled to one or more respective codebooks and/or one ormore precoder controllers. In particular, as illustrated, the basebandprecoder 406 receives configuration parameters (e.g., a vector withcoefficients defining operation(s) of the baseband precoder 406) from amemory structure 410 and the RF precoder 408 receives configurationparameters from a memory structure 412. Each of these memory structures,which can include persistent memory, working memory, databases, virtualdata structures, shift registers, or any other suitable physical orvirtual memory structure can be communicably coupled to, and controlledby, a mutual precoder controller 414, described in greater detail below.

The hybrid precoder chain 402 a couples output of the baseband precoder406 into an input of a digital to analog converter 416. Analog output ofthe digital to analog converter 416 can be provided as input to anappropriate RF chain which can include one or more up-converters,filters, amplifiers, and so on. Collectively, any component that mayform a portion of an RF chain configured to receive baseband analog dataand to output an RF signal is represented as the RF chain 418. The RFchain 418 provides output that is received as input to an antenna array420 that, in response to the signal(s) received from the RF chain 418,can generate a lobe pattern into the local RF environment 422.

As noted above, the lobe pattern generated by the antenna array 420 isdefined, at least in part, by the baseband precoder 406 and the RFprecoder 408 which, in turn are controlled by the mutual precodercontroller 414.

The mutual precoder controller 414 can be configured to selectconfiguration parameters for both the baseband precoder 406 and the RFprecoder 408. In particular, in many embodiments the mutual precodercontroller 414 can be configured to leverage known channel information(e.g., obtained by beamtraining, received from another device within thesame RF environment, and so on) to find or estimate optimalconfiguration parameters for both BB and RF precoders. For example, inone construction, an orthogonal matching pursuit algorithm (“OMP”) canbe leveraged by the mutual precoder controller 414.

The OMP algorithm can receive, as input (among other values orconfiguration parameters, such as RF chain counts, or antenna counts),initial values for each of the baseband precoder 406 and RF precoder408. Therewith, the OMP algorithm can iteratively determine combinationsof configuration parameters that result in the highest inner productuntil a stop condition is met, or iteration has completed. It may beappreciated by a person of skill in the art that this is merely one,simplified, example operation of the mutual precoder controller414—other algorithms and operational configurations are possible.

Regardless of configuration, the mutual precoder controller 414 isconfigured to select configuration parameters for both the basebandprecoder 406 and the RF precoder 408 that minimize self-interferencereceived at a receive co-located (e.g., within the same transceiverdevice) with the hybrid precoder chain 402 a.

For example, the mutual precoder controller 414 can be configured todirect a null toward receiver circuitry. In other words, the mutualprecoder controller 414 may be configured to operate the antenna array420 in a manner that generates a lobe pattern that minimizes RF energyemitted toward the receiver electronics.

In a more specific phrasing, the mutual precoder controller 414 candetermine configuration parameters for the baseband precoder 406 and theRF precoder 408 based on an initial assumption that the interferencechannel that beams should be directed to avoid is a channel definedbetween the transmitter and the receiver of the same transceiver device.

As a simple example, a conventional transceiver leveraging hybridbeamforming may select a path to an endpoint device using an algorithmthat is configured to optimize for on the signal to noise plusinterference radio (“SINR”). This path may be one of many paths thatexist between a transmitter and the endpoint device.

By contrast, embodiments described herein operate the mutual precodercontroller 414 in a different manner. In particular, the mutual precodercontroller 414 is configured to select a path (or more than one path)that minimizes interference back to the transceiver's own receivercircuitry.

To visualize such a construction, an example is provided. In thisexample, two transceiver devices are operated in an RF environment thatincludes one or more RF reflective surfaces. A small RF reflectivesurface sits between the transceiver devices, and is sized such that aportion of RF energy emitted toward the surface is reflected back to thesource of that RF energy. In this example, the first transceiver,operating a hybrid beamforming architecture, may determine (e.g., viabeamtraining or another method) that the best path between the firsttransceiver and the second transceiver is line of sight, toward thesmall RF reflective surface. In this conventional construction, RFenergy emitted by the first transceiver is reflected from the surfaceback to the first transceiver. This reflected energy isself-interference.

By contrast, embodiments described herein optimized in a differentmanner. Continuing the example provided above, the mutual precodercontroller 414 may determine that a path that directs a beam toward adifferent reflective surface in the local RF environment avoidsilluminating the small RF reflective surface altogether and, as aresult, reduces and/otherwise mitigates self-interference.

The foregoing example is understood to be simplified; in a practicalapplication of the embodiments described herein, and in particular thoserelated to operation of the mutual precoder controller 414, pathselection may be a more computational complicated task. However, bydesigning the mutual precoder controller 414 to prioritize path designand/or construction in a manner that reduces self-interference,full-duplex in-band communication can be enabled. In particular, asnoted above, the mutual precoder controller 414 can be configured toprioritize lobe patterns that steer nulls toward the receiver and/or canbe configured to prioritize paths that minimize self-interference.

In further embodiments, receiver electronics of a transceiver can belikewise configured to prioritize paths that avoid self-interferenceintroduced by transmitter electronics of the same transceiver device. Ina simple, non-limiting phrasing, a receiver device can be configured toprefer channels (and/or may attempt to communicate to a remote devicetransmitting a signal to that receiver, for example during abeamtraining operation) that avoid interference created by thetransmitter co-located with that receiver device.

For example, FIG. 4B depicts a simplified signal flow diagram of ahybrid digital/analog beamforming controller of a receiver of a wirelesscommunication system, as described herein.

The receiver of the transceiver 400 includes a hybrid combiner chain 402b that is configured in a similar manner as the hybrid precoder chain402 a. In particular, the hybrid combiner chain 402 b is configured toreceive RF energy from the local RF environment 422 at an antenna array424. The antenna array 424 is coupled via a bus (or other multi-line,multi-chain coupling structure) to an RF combiner 426. As with thehybrid precoder chain 402 a shown in FIG. 4A, the hybrid combiner chain402 b also has a corresponding baseband combiner 428. Each of the RFcombiner 426 and the baseband combiner 428 are configured to receivevectors, arrays, or other memory structures to define one or moreoperations thereof, such as what phase delays and/or amplitudemodifications to perform to which signals at which time. As with thehybrid precoder chain 402 a, the hybrid combiner chain 402 b includes amemory structure 430 and a memory structure 432 that each store and/orotherwise provide these configuration parameters to the RF combiner 426and the baseband combiner 428, respectively. A mutual combinercontroller 434 is communicably and/or conductively coupled to eachcombiner and is configured to control operations thereof.

As with the hybrid precoder chain 402 a, the hybrid combiner chain 402 balso includes other elements and operational components, some of whichare shown in the simplified view show in FIG. 4B. For example, outputfrom the antenna array 424 is provided as input to the RF combiner 426.The RF combiner 426 provides as output input to an RF chain 436configured to filter and/or down-convert RF signals output from thecombiner to baseband. Output from the RF chain 436 is provided as inputto an analog to digital converter 438 which is configured to output oneor more digital values that can be provided as input to the basebandcombiner 428.

The mutual combiner controller 434 can be configured to operate in muchthe same manner as described above with respect to the mutual precodercontroller 414. In particular, the mutual combiner controller 434 can beconfigured to operate the baseband combiner 428 and the RF combiner insuch a manner as to prioritize signals sent from directions along pathsthat do not contain substantial self-interference that originated fromthe transceiver device itself. For example, while beamtraining withanother transceiver device, the mutual combiner controller 434 canprioritize a path, code, or other configuration that minimizesself-interference.

These foregoing embodiments depicted in FIGS. 4A-4B and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

For example, generally and broadly, it may be appreciated that a hybridarchitecture such as described above can be controlled on either thetransmitter side or the receiver side to reduce self-interference. Inone example, a precoder controller or a combiner controller can beconfigured to prioritize a path through a local RF environment thatminimizes self-interference to a minimum level, thereby enablingfull-duplex in-band communication.

In another more general phrasing, embodiments described herein enable afrequency-selective fully digital beamforming architecture. In otherwords, the mutual controllers discussed above in reference to FIGS.4A-4B can be operated to prefer and/or optimize for particularfrequencies or bands that result in the lowest self-interference in agiven RF environment. As a result of this construction, a transceiverdevice can minimize self-interference which, in turn, can enable thattransceiver to simultaneously transmit and receive within the same bandsof frequencies at the same time.

In further embodiments, other methods of cancelling and/or reducingself-interference are possible. For example, generally and broadly,FIGS. 5A-5B depict an example architecture in which a transceiver asdescribed herein can include one more self-interference filters. Morespecifically, these embodiments contemplate self-interferencecancelation in either or both the RF domain or the BB domain.

For example, FIG. 5A depicts a simplified signal flow diagram 500 a ofan in-band full duplex transceiver 502 of a wireless communicationsystem, as described herein.

As with other embodiments described herein, the in-band full duplextransceiver 502 includes a transmitter side and a receiver side. Thetransmitter side is configured to receive a data stream, convert thatdigital data into an analog baseband signal, up-convert the basebandsignal into an RF signal, and apply the resulting RF signal to anantenna array as input. In response, the antenna array emits RF energyinto the ambient, local, RF environment according to a particular lobepatter. The lobe pattern emitted from the antenna array is defined, asnoted above, by one or more precoders, which may operate in either thedigital or analog domain.

More specifically, the in-band full duplex transceiver 502 includes atransmit side that is configured to receive a data stream at a digitalinput 504. The digital input 504 can be communicably coupled to anysignal source, such as a backhaul in the case of a base station or suchas a processor in the case of a personal electronic device. The digitalinput 504 can be configured to receive digital data according to anyform or format. The digital input 504 may be an optical input or aconductive input.

The in-band full duplex transceiver 502 also includes a receive sidethat is configured to receive one or more RF signals from the local RFenvironment, to down-convert those signals into baseband signals, and toconvert those baseband signals into digital data that may be provided toanother component or system via a digital output 506. The digital output506 can be communicably coupled to any electronic device or network,such as a backhaul in the case of a base station or such as a processorin the case of a personal electronic device. The digital output 506 canbe configured to transmit digital data according to any form or format.In many embodiments, the transmitted digital data output from thedigital output 506 is provided as a data stream. As with the digitalinput 504, the digital output 506 may be an optical output or aconductive output.

Regarding the transmitter side of the in-band full duplex transceiver502, the digital input 504 can be communicably and/or conductivelycoupled either directly or indirectly to an input of a baseband precoder508 that feeds its output to a digital to analog converter 510configured to output an analog signal. As with other embodimentsdescribed herein the baseband precoder 508 is configured to perform oneor more beamforming operations, such as those described above withreference to FIGS. 4A-4B. More specifically, the baseband precoder 508may be configured to output signals to the digital to analog converter510 that, when up-converted by an RF chain 512 and supplied as input toan antenna array, steer at least one lobe or at least one null outputfrom the antenna array in a particular direction in the local RFenvironment that minimizes self-interference back to the receive side ofthe in-band full duplex transceiver 502. More specifically, the basebandprecoder 508 can be configured as described above; this description isnot repeated.

In many construction, output from the RF chain 512 can be modified by anRF precoder 514. As with the baseband precoder 508, the RF precoder 514can be configured to output signals to the antenna array 516 that steerat least one lobe and/or at least one null output form the antenna array516 in a particular direction that minimizes self-interference back tothe receive side of the in-band full duplex transceiver 502. Similar tothe baseband precoder 508, it may be appreciated that the RF precoder514 can be configured as described above; this description is notrepeated.

As noted above, the in-band full duplex transceiver 502 also includes areceive side configured to receive one or more signals from the ambientRF environment and to convert those signals into one or more datastreams that may be output via the digital output 506. In addition, thein-band full duplex transceiver 502 may include one or moreself-interference filters to leverage information known about whatsignal(s) the transmitter side is transmitting to cancel or mitigateportions of those signals received by the receive side of the in-bandfull duplex transceiver 502. As illustrated, two self-interferencecancelation filters are shown—a first is identified as the RFself-interference cancellation filter 518 and a second is identified asthe baseband self-interference cancellation filter 520.

More specifically, the receiver side of the in-band full duplextransceiver 502 includes an antenna array 522 similar to the antennaarray 516. The antenna array 522 can include the same or a differentnumber of antennas as the antenna array 516. In some cases, the antennaarray 516 and the antenna array 522 may be the same antenna array,although this is not required of all embodiments.

Output from the antenna array 522 is provided as input to a junction524. In some examples, the junction 524 may be referred to as an RFcombiner, but for an abundance of clarity and to functionally separatedescriptions and operations of digitally-controlled combiners associatedwith beamforming operations, element 524 depicted in FIG. 5 is referredto as a junction 524.

The junction 524 can be configured to merge, in the RF domain, a signaloutput from the RF self-interference cancellation filter 518 with a rawRF signal received from the antenna array 522. The function andoperation of the junction 524 and the RF self-interference cancellationfilter 518 are described in greater detail below.

Output from the junction 524 is provided as input to an RF combiner 526.As with the combiners described above, the RF combiner 526 can beconfigured to combine signals in a manner (e.g., with particular phasedelays and so on) in a manner that minimizes self-interference. Similarto the precoders described above, it may be appreciated that the RFcombiner 526 can be configured as described above; this description isnot repeated.

Output from the RF combiner 526 is provided as input to an RF chain 528that is configured to down-convert the RF signals output from thejunction into a baseband signal which, thereafter, can be converted intoa digital signal by an analog to digital converter 530. Output from theanalog to digital converter 530 is provided as input to a basebandcombiner 532 that, like the RF combiner 526 can be configured tofunction as a portion of a beamforming filter; this description is notrepeated.

Output from the baseband combiner 532 is provided as digital output viathe digital output 506.

As a result of this construction, the in-band full duplex transceiver502 can be configured to leverage its own transmit signal forcancellation purposes. For example, in one embodiment, the in-band fullduplex transceiver 502 is operated in an RF environment in which thereceive side receives a single “echo” of self-interference at aparticular delay. In this example, the RF self-interference cancellationfilter 518 can be configured to apply a phase shift to at least onesignal it receives from the RF precoder 514. The phase shift may beselected to be precisely equal to the delay of the echo received by thereceive side in the local RF environment. In addition, the RFself-interference cancellation filter 518 can be configured to invertthe phase delayed signal. In this manner, and as a result of thistechnique, a single echo can be canceled at the junction 524.

A person of skill in the art will readily appreciate that “single-echo”RF environments are uncommon. As such it may be appreciated that in manypractical applications, the RF self-interference cancellation filter 518may be configured to apply multiple delays and/or multiple phase shiftsto multiple different signals output from the RF precoder 514 in orderto cancel as many echoes of self-interference that may be present in aparticular environment. For mmWave implementations, the number of echoesmay be smaller than lower-frequency implementations and, as such, the RFself-interference cancellation filter 518 may enjoy a simpler design formmWave implementations.

In some examples, the RF self-interference cancellation filter 518 canperform one or more autocorrelation or cross correlation operations withsignals received at the antenna array 522 to precisely determine whatmultipath effects can and should be canceled in the RF domain.

In other cases, the RF self-interference cancellation filter 518 can beimplemented as a completely analog filter. In particular, the RFself-interference cancellation filter 518 can include an array or matrixof individual phase shifters or amplitude adjusters that coupledindividual signal lines driving individual antennas or subgroups of theantenna array 516 to individual signal lines received from individualantennas or subgroups of the antenna array 522.

In many cases, the baseband self-interference cancellation filter 520can be configured to operate with the RF self-interference cancellationfilter 518. For example, in some cases, a machine learning algorithmand/or other trained algorithm can receive, as input, the digital inputsignal, the RF counterpart to that signal, an RF receive signal, and/ora received BB signal. In such examples, the algorithm may beconfigurable to determine optimal parameters for the basebandself-interference cancellation filter 520 and/or the RFself-interference cancellation filter 518 in order to mitigateself-interference to the largest extent. Such a learning algorithm canbe implemented in a number of suitable ways, but in one example isimplemented as a neural network trained in an manner that presumes thatthe only interference present in an RF environment originates from thetransceiver device itself.

In a more simple phrasing, a machine learning algorithm (which can alsobe referred to as a predictive model, an artificial intelligenceinstance, and so on) can be trained to select parameters for bothbaseband and RF self-interference filters in order to minimize effectsof self-interference when operating in full-duplex communication modes.

The foregoing example embodiment described in reference to FIG. 5A ismerely one example and it may be appreciated that other embodiments canbe constructed or architected in any suitable manner. In particular, itmay be appreciated that self-interference filters can receive input fromany suitable location or signal source within a transceiver, asdescribed herein. For example, FIG. 5B depicts a simplified signal flowdiagram 500 b depicting the in-band full duplex transceiver 502 in whichthe RF self-interference cancellation filter 518 receives input from theRF chain 512 instead of the RF precoder 514.

More generally and broadly, it may be appreciated that a machinelearning controller and/or a precoder controller and/or a combinercontroller can be configured to receive information from, and/or signalinput from, any suitable portion of a transceiver transmit side orreceiver side.

These foregoing embodiments depicted in FIGS. 5A-5B and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

For example, generally and broadly it may be appreciated that theforegoing embodiments describe and reference various techniques forminimizing self-interference when operating a transceiver in full-duplexmodes. In some cases, beamforming controllers on both the transmitterside (e.g., precoders) and the receive side (e.g., combiners) can beused to prefer communication paths (e.g., channels) that avoidinterference as much as possible and/or that are configured to generatelobe patterns that direct nulls toward receiver side electronics orantenna arrays.

In addition, the foregoing embodiments contemplate self-interferencefilters that operate to mitigate self-interference based on informationknown about signals already-transmitted by a transmitter side of thetransceiver. In further implementations of these embodiments, machinelearning tools can be leveraged to select optimal parameters to cancelself-interference in either or both the RF or BB domains. Suchself-interference can not only account for environmentalself-interference (e.g., transmitted signals that reflect or otherwisearrive at receiver-side antenna arrays) but also internalself-interference or non-ideality effects, such as non-ideal operationsof one or more filters, RF chain components, and so on.

Each of these foregoing described techniques and architectures can beused individually or collectively to reduce self-interference effects tothe same transceiver device. In other cases, these techniques can beleveraged to the inter-operation of multiple co-located electronicdevices. For example, FIG. 6 depicts a simplified system diagram of anin-band full duplex transceiver co-located with another transceiveroperating in the same band, system as described herein. In particular, acommunications transceiver, such as described above can be operated witha mmWave radar array. In a more simple phrasing, FIG. 6 depicts a systemof wireless transceivers (or a system of RF devices) that can co-operatein the same band by leveraging the systems and methods described herein.

Generally and broadly, the embodiment shown in FIG. 6 depicts an examplearrangement in which an in-band full-duplex transceiver described hereinis positioned relative to another electronic device in a manner thatminimizes the effects of interference on the second device. Morespecifically, by co-locating transmitters and co-locating receivers, theabove-described benefits of reducing self-interference at the receiverof the transceiver can be extended to the receiver side of the secondelectronic device.

More specifically, a simplified system diagram 600 shows two co-locatedmmWave systems. Each system includes a transmit side and a receive side.As noted above, to reduce interference with the second system by thefirst system, the transmit sides of both systems can be arrangedtogether into a transmit pairing 602. Similarly, receive sides of bothsystems can be arranged together into a receive pairing 604.

The illustrated embodiment depicts a communications transceiver 606co-operating with (in the same bands) a radar system 608. In particular,a transmit side 610 of the communications transceiver is physicallypositioned adjacent to a transmit side of the radar system 608.Similarly, the receive side 612 of the communications transceiver 606 ispositioned physically proximate to the receive side of the radar system608.

As a result of this positioning, the radar system 608 and thecommunications transceiver 606 can co-operate within the same bands, asthe receive side of the radar system 608 is positioned physically closeenough to the receive side 612 of the communications transceiver 606 soas to benefit from the self-interference cancellation effects achievedby intentional beamforming of signals emitted from the transmit side610, such as described above.

These foregoing embodiments are presented merely as examples, and arenot exhaustive of the configurations of constructions of a systemconfigured to operate as described herein. In particular, more generallyand broadly, a transceiver as described herein can be understood toinclude one or more beamforming controllers, one or moreself-interference cancellation filters, and/or one or more processors,memory, or other electronics (e.g., which may implement one or moremachine learning algorithms to assist with control of one or moreoperations described herein). An example simplified system diagram isprovided in FIG. 7.

In particular, FIG. 7 depicts a simplified system diagram of an in-bandfull duplex transceiver 700, system as described herein. The in-bandfull duplex transceiver 700 can be disposed within a housing 702 thatcan enclose and support one or more functional or operational componentsof the in-band full duplex transceiver 700.

In particular, disposed within the housing 702 the in-band full duplextransceiver 700 includes a processor 704 and a memory 706. The processor704 can be any processor or controller as described herein including oneor more baseband or RF combiner/precoder controllers, one or more mutualcontrollers, one or more self-interference filters, and so on. Asdescribed herein, the term “processor” refers to any software and/orhardware-implemented data processing device or circuit physically and/orstructurally configured to instantiate one or more classes or objectsthat are purpose-configured to perform specific transformations of dataincluding operations represented as code and/or instructions included ina program that can be stored within, and accessed from, a memory. Thisterm is meant to encompass a single processor or processing unit,multiple processors, multiple processing units, analog or digitalcircuits, or other suitably configured computing element or combinationof elements.

The processor 704 is communicably coupled to the memory 706 which caninclude a working memory and/or a persistent memory. In one exampleconstruction, the processor 704 is configured to access apersistent/durable portion of the memory 706 to obtain one or moreexecutable assets that can be loaded by the processor 704 into a workingportion of the memory 706. By doing so, the processor 704 may cause tobe instantiated one or more software applications that, when executed bythe processor can be configured to perform, coordinate, schedule,monitor, or otherwise assist with one or more operations of the in-bandfull duplex transceiver 700 as described herein. For example, in oneconstruction, the processor 704 is configured to instantiate abeamforming control application that controls baseband and/or RFprecoders or combiners, such as the beamforming controllers 708, 710. Inother cases, the processor 704 can be configured to instantiate amachine learning or predictive model application that is configured tocontrol parameters of one or more self-interference filters, such as abaseband self-interference filter 712 or RF self-interference filter714. In yet other cases, other application instances can be instantiatedby the processor 704 in order

These foregoing embodiments depicted in FIGS. 2A-7 and the variousalternatives thereof and variations thereto are presented, generally,for purposes of explanation, and to facilitate an understanding ofvarious configurations and constructions of a system, such as describedherein. However, it will be apparent to one skilled in the art that someof the specific details presented herein may not be required in order topractice a particular described embodiment, or an equivalent thereof.

Thus, it is understood that the foregoing and following descriptions ofspecific embodiments are presented for the limited purposes ofillustration and description. These descriptions are not targeted to beexhaustive or to limit the disclosure to the precise forms recitedherein. To the contrary, it will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

FIG. 8 is a flowchart depicting example operations of a method of usinga hybrid digital/analog beamforming architecture for self-interferencecancellation, such as described herein. The method 800 can be performedby any suitable hardware or software or combination thereof, such as theprocessor 704 depicted in FIG. 7.

The method 800 includes operation 802 in which a codebook is received asinput. The codebook can include information useful for operating one ormore analog RF beamforming precoders or combiners. The codebook can takeany suitable form or format. In many examples, the codebook takes theform of a memory structure retrieved from a database, but this is notrequired of all embodiments.

The method 800 includes operation 804 in which channel information isreceived and/or a beamtraining operation is performed. Finally, atoperation 806, the codebook data and/or channel information can be usedas input to an orthogonal matching pursuit algorithm in order todetermine configuration parameters for an analog precoder and/or adigital precoder. In many embodiments, these configuration parameterstake the form of a vector, but this is not required of all embodiments.

As described above, this technique of determining configurationparameters for analog and digital sides of a transceiver's beamformingarchitecture can be leveraged to quickly and accurately determine acommunication channel and/or path from transmitter to receiver thatminimizes self-interference.

FIG. 9 is a flowchart depicting example operations of a method of usinga self-interference cancellation filters for self-interferencecancellation, such as described herein. As with the method 800, themethod 900 can be performed by any suitable hardware or software orcombination thereof, such as the processor 704 depicted in FIG. 7.

The method 900 optionally includes operation 902 at which a beamtrainingoperation can be performed and/or channel information and interferenceinformation can be obtained in another manner.

The method 900 also includes operation 904 at which one or more RFtransmit signals are received as input to a self-interferencecancellation filter. Next at operation 906, a cancellation signal can begenerated from the RF transmit signals received at operation 904.Finally at operation 908, the cancellation signal can be combined with areceived signal to mitigate effects of self-interference.

FIG. 10 is a flowchart depicting example operations of a method ofcontrolling multiple co-located transceivers configured to transmitand/or receive in the same band, such as described herein. The method1000 can be performed by any suitable hardware or software orcombination thereof, such as the processor 704 depicted in FIG. 7.

The method 1000 includes operation 1002 in which input from a radarsystem operating in the mmWave band is obtained. The input can obtaininformation about the local RF environment.

Next at operation 1004, the method 1000 advances to estimate channelinterference based, at least in part, on the information obtained fromthe radar system at operation 1002. In addition, once the channelinformation is estimated, a cancellation signal can be generated.

Finally, the method 1000 advances to operation 1006 at which thecancellation signal is combined with a received signal to mitigateinterference from a transmitted signal, otherwise (as noted above)referred to as self-interference.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list. Thephrase “at least one of” does not require selection of at least one ofeach item listed; rather, the phrase allows a meaning that includes at aminimum one of any of the items, and/or at a minimum one of anycombination of the items, and/or at a minimum one of each of the items.By way of example, the phrases “at least one of A, B, and C” or “atleast one of A, B, or C” each refer to only A, only B, or only C; anycombination of A, B, and C; and/or one or more of each of A, B, and C.Similarly, it may be appreciated that an order of elements presented fora conjunctive or disjunctive list provided herein should not beconstrued as limiting the disclosure to only that order provided.

One may appreciate that although many embodiments are disclosed above,that the operations and steps presented with respect to methods andtechniques described herein are meant as exemplary and accordingly arenot exhaustive. One may further appreciate that alternate step order orfewer or additional operations may be required or desired for particularembodiments.

Although the disclosure above is described in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied, alone or in various combinations, to one or more of the someembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments but is instead defined by the claims herein presented.

What is claimed is:
 1. A wireless transceiver for an in-band full duplexradio frequency (“RF”) communication system, the wireless transceivercomprising: a transmit side comprising: a digital input receiving afirst data stream as input; a first precoder receiving the data streamas input; a digital to analog converter receiving output of the firstprecoder as input; a first RF chain receiving output of the digital toanalog converter as input; a second precoder receiving output of the RFchain as input; and a first antenna array receiving output of the secondprecoder as input and configured to emit RF energy into a local RFenvironment; a receive side comprising: a second antenna array receivingRF energy from the local RF environment; a first combiner receiving thereceived RF energy as input; a second RF chain receiving output of thefirst combiner as input; an analog to digital converter receiving outputof the second RF chain as input; a second combiner receiving output ofthe analog to digital converter as input; and a digital output receivingoutput of the second combiner as input and configured to provide asecond data stream as output; and a controller providing configurationparameters to both the first precoder and the second precoder based onchannel state information, the configuration parameters configured tominimize the RF energy emitted by the first antenna array that returnsto the second antenna array.
 2. The wireless transceiver of claim 1,comprising a self-interference cancellation filter coupling output ofthe second precoder to input of the first combiner.
 3. The wirelesstransceiver of claim 2, wherein: the self-interference cancellationfilter is a first self-interference cancellation filter; and thewireless transceiver comprises a second self-interference cancellationfilter coupling output of the first precoder to input of the secondcombiner.
 4. The wireless transceiver of claim 3, wherein the firstself-interference cancellation filter cancels a first portion ofself-interference and the second self-interference cancellation filtercancels a second portion of self-interference.
 5. The wirelesstransceiver of claim 4, wherein the first self-interference cancellationfilter introduces a phase shift to output of the second precoder.
 6. Thewireless transceiver of claim 4, wherein: the configuration parametersare first configuration parameters and; the controller is configured toapply second configuration parameters to the first self-interferencecancellation filter and the second self-interference cancellationfilter, the second configuration parameters configured to minimize theRF energy emitted by the first antenna array that returns to the secondantenna array and is received at the first combiner.
 7. The wirelesstransceiver of claim 6, wherein the controller is configured toinstantiate an instance of a trained predictive model; and the instanceof the trained predictive model is configured to provide the secondconfiguration parameters as output.
 8. The wireless transceiver of claim7, wherein the instance of the trained predictive model comprises aneural network configured to receive as input at least one of the firstdata stream or the second data stream.
 9. The wireless transceiver ofclaim 1, wherein the controller is configured to access a codebook toprovide configuration parameters to the second precoder.
 10. Thewireless transceiver of claim 1, wherein the RF energy is emitted intothe local RF environment by the first antenna array at at least onefrequency between 1 GHz and 300 GHz.
 11. The wireless transceiver ofclaim 1, wherein: the configuration parameters are first configurationparameters; and the controller is configured to provide secondconfiguration parameters to both the first combiner and the secondcombiner based on the channel state information, the secondconfiguration parameters configured to minimize the RF energy emitted bythe first antenna array that returns to the second antenna array. 12.The wireless transceiver of claim 1, wherein the second antenna arrayand the first antenna array are portions of a third antenna array.
 13. Asystem of radio frequency (“RF”) devices, the system comprising: a firsttransceiver comprising: a first transmit side comprising a firsttransmit side antenna array; and a first receive side comprising a firstreceive side antenna array; and a second transceiver comprising: asecond transmit side comprising: a baseband precoder and an RF precoder;and a second transmit side antenna array; a second receive sidecomprising a second receive side antenna array; and a controllerproviding configuration parameters to both the baseband precoder and theRF precoder based on channel state information, the configurationparameters configured to minimize the RF energy emitted by the secondtransmit side antenna array that returns to the first receive sideantenna array and the second receive side antenna array.
 14. The systemof claim 13, wherein the first receive side antenna array is co-locatedwith the second receive side antenna array.
 15. The system of claim 14,wherein the first transmit side antenna array is co-located with thesecond transmit side antenna array.
 16. The system of claim 13, whereinthe first transceiver is one of a radar transceiver, an RF jammingsystem, or an electronic warfare system.
 17. The system of claim 13,wherein the first transceiver and the second transceiver are configuredto operate in at least one overlapping band.
 18. A method of operating awireless transceiver for an in-band full duplex radio frequency (“RF”)communication system, the method comprising: receiving channel stateinformation; determining first configuration parameters for a basebandprecoder of the wireless transceiver based on the channel stateinformation, the first configuration parameters configured to minimizeself-interference received at a receive antenna of the wirelesstransceiver; determining second configuration parameters for an RFprecoder of the wireless transceiver based on the channel stateinformation, the second configuration parameters configured to minimizeself-interference received at the receive antenna of the wirelesstransceiver; and applying the first and second configuration parametersto the baseband precoder and the RF precoder, respectively.
 19. Themethod of claim 18, further comprising: determining third configurationparameters for an RF self-interference filter of the wirelesstransceiver based on the channel state information, the thirdconfiguration parameters configured to minimize self-interferencereceived at an RF combiner of the wireless transceiver; determiningfourth configuration parameters for a baseband self-interference filterof the wireless transceiver based on the channel state information, thefourth configuration parameters configured to minimize self-interferencereceived at a baseband combiner of the wireless transceiver; applyingthe third and fourth configuration parameters to the RFself-interference filter and the baseband self-interference filter,respectively.
 20. The method of claim 18, wherein determining the firstconfiguration parameters and the second configuration parameters isperformed by leveraging an orthogonal matching pursuit algorithm.